Use Terraform to deploy juju charm on microk8s

Docker https://developer.hashicorp.com/terraform/tutorials/docker-get-started/docker-build
Miscrok8s https://mikelynchgames.com/software-development/getting-started-with-local-kubernetes-developing-microservices-with-microk8s/

Juju https://discourse.charmhub.io/t/introducing-the-juju-terraform-provider/6939

• juju/microk8s install

$ sudo snap install microk8s --channel=1.32-strict/stable
...
$ sudo snap install juju --channel=3.6/stable
...

• juju/microk8s setup

$ sudo microk8s enable hostpath-storage
...

$ sudo juju controllers
Use --refresh option with this command to see the latest information.

Controller  Model  User   Access     Cloud/Region         Models  Nodes  HA  Version
overlord*   -      admin  superuser  localhost/localhost       1      -   -  (unknown)  

$ kubectl get pods --all-namespaces 
NAMESPACE     NAME                                       READY   STATUS    RESTARTS   AGE
kube-system   calico-kube-controllers-5947598c79-brrfz   1/1     Running   0          27s
kube-system   calico-node-m8vnf                          1/1     Running   0          16s
kube-system   coredns-79b94494c7-r4lq4                   1/1     Running   0          11s
kube-system   hostpath-provisioner-c778b7559-fr9kx       1/1     Running   0          4s

$ sudo juju bootstrap microk8s micro 
Creating Juju controller "micro" on microk8s/localhost
Bootstrap to Kubernetes cluster identified as microk8s/localhost
Creating k8s resources for controller "controller-micro"
Starting controller pod
Bootstrap agent now started
Contacting Juju controller at 10.152.183.100 to verify accessibility...

Bootstrap complete, controller "micro" is now available in namespace "controller-micro"

Now you can run
        juju add-model <model-name>
to create a new model to deploy k8s workloads.

$ sudo juju controllers
Use --refresh option with this command to see the latest information.

Controller  Model  User   Access     Cloud/Region         Models  Nodes  HA  Version
micro*      -      admin  superuser  microk8s/localhost        1      1   -  3.6.4      
overlord    -      admin  superuser  localhost/localhost       1      -   -  (unknown)  

$ kubectl get pods --all-namespaces 
NAMESPACE          NAME                                       READY   STATUS    RESTARTS   AGE
controller-micro   controller-0                               3/3     Running   0          2m21s
controller-micro   modeloperator-58798bccc-hk9hj              1/1     Running   0          59s
kube-system        calico-kube-controllers-5947598c79-brrfz   1/1     Running   0          4m2s
kube-system        calico-node-m8vnf                          1/1     Running   0          3m51s
kube-system        coredns-79b94494c7-r4lq4                   1/1     Running   0          3m46s
kube-system        hostpath-provisioner-c778b7559-fr9kx       1/1     Running   0          3m39s

$ sudo juju add-model test
Added 'test' model on microk8s/localhost with credential 'microk8s' for user 'admin'
$ sudo juju switch test
$ sudo juju models
Controller: micro

Model       Cloud/Region        Type        Status     Units  Access  Last connection
controller  microk8s/localhost  kubernetes  available  1       admin  just now
test*       microk8s/localhost  kubernetes  available  5       admin  4 seconds ago

$ kubectl get pods --all-namespaces
NAMESPACE          NAME                                       READY   STATUS    RESTARTS   AGE
controller-micro   controller-0                               3/3     Running   0          17m
controller-micro   modeloperator-78645f9fb5-8s9sq             1/1     Running   0          17m
test               modeloperator-7c47595567-nwl8q             1/1     Running   0          19s
kube-system        calico-kube-controllers-5947598c79-qs68c   1/1     Running   0          31m
kube-system        calico-node-fwbxl                          1/1     Running   0          31m
kube-system        coredns-79b94494c7-qjwjd                   1/1     Running   0          31m
kube-system        hostpath-provisioner-c778b7559-6sngm       1/1     Running   0          31m

• microk8s setup

$ sudo usermod -a -G snap_microk8s $USER
$ sudo chown -R $USER ~/.kube
$ newgrp microk8s
$ alias kubectl='KUBE_EDITOR=vi microk8s kubectl'
$ source <(kubectl completion bash)

• terraform install

$ sudo snap install terraform --classic
...

• terraform apply (Remember to update the juju provider version in the YAML file to the latest one.)

### Grab the Terraform file
$ wget -qO k8s-example.tf https://gist.githubusercontent.com/fourdollars/fdab97c7da29a2dd70f46a726daa9dfd/raw/0db6a002569ee5dd90977a52d2145c47702a8462/k8s-example.tf

### Initialise the provider
$ terraform init

### Run Terraform Plan, check the output
$ sudo terraform plan

### Deploy the resources, skip the approval
$ sudo terraform apply -auto-approve

$ sudo juju switch dev
$ sudo juju status --relations
Model  Controller  Cloud/Region        Version  SLA          Timestamp
dev    micro       microk8s/localhost  3.6.4    unsupported  13:57:30Z

App            Version          Status  Scale  Charm           Channel        Rev  Address         Exposed  Message
grafana        9.5.3            active      1  grafana-k8s     latest/stable  138  10.152.183.34   no       
hello-kubecon                   active      1  hello-kubecon   latest/stable   19  10.152.183.232  no       
parca          0.18.0-800a6bb7  active      1  parca-k8s       latest/stable  248  10.152.183.112  no       
prometheus     2.52.0           active      1  prometheus-k8s  latest/stable  232  10.152.183.162  no       
zinc           ...              active      1  zinc-k8s        latest/stable  176  10.152.183.199  no       

Unit              Workload  Agent      Address      Ports  Message
grafana/0*        active    idle       10.1.98.237         
hello-kubecon/0*  active    idle       10.1.98.236         
parca/0*          active    idle       10.1.98.230         
prometheus/0*     active    executing  10.1.98.238         
zinc/0*           active    idle       10.1.98.229         

Integration provider         Requirer                     Interface           Type     Message
grafana:grafana              grafana:grafana              grafana_peers       peer     
grafana:replicas             grafana:replicas             grafana_replicas    peer     
parca:metrics-endpoint       prometheus:metrics-endpoint  prometheus_scrape   regular  
prometheus:grafana-source    grafana:grafana-source       grafana_datasource  regular  
prometheus:prometheus-peers  prometheus:prometheus-peers  prometheus_peers    peer     
zinc:grafana-dashboard       grafana:grafana-dashboard    grafana_dashboard   regular  
zinc:metrics-endpoint        prometheus:metrics-endpoint  prometheus_scrape   regular  
zinc:profiling-endpoint      parca:profiling-endpoint     parca_scrape        regular  
zinc:zinc-peers              zinc:zinc-peers              zinc_peers          peer     

$ kubectl get pods --all-namespaces
NAMESPACE          NAME                                       READY   STATUS    RESTARTS   AGE
controller-micro   controller-0                               3/3     Running   0          48m
controller-micro   modeloperator-78645f9fb5-8s9sq             1/1     Running   0          48m
dev                grafana-0                                  3/3     Running   0          25m
dev                hello-kubecon-0                            2/2     Running   0          26m
dev                modeloperator-df478b697-4q9fz              1/1     Running   0          26m
dev                parca-0                                    2/2     Running   0          26m
dev                prometheus-0                               2/2     Running   0          24m
dev                zinc-0                                     2/2     Running   0          26m
kube-system        calico-kube-controllers-5947598c79-qs68c   1/1     Running   0          62m
kube-system        calico-node-fwbxl                          1/1     Running   0          62m
kube-system        coredns-79b94494c7-qjwjd                   1/1     Running   0          62m
kube-system        hostpath-provisioner-c778b7559-6sngm       1/1     Running   0          62m

### Destroy the resources, skip the approval
$ sudo terraform destroy -auto-approve